<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>iframe测试体验页面无刷新</title>
    <script>
        function go(){
            //所有的变量提前获取
            let url = document.getElementById("url").value;
            document.getElementById("iframe1").src=url;

        }


    </script>
</head>
<body>

    <div>
        <p>请输入地址:</p>
        <p><input type="text" id="url" value="">
            <input TYPE="button" value="提交" onclick="go()">
        </p>

    </div>

    <div>
        <iframe id="iframe1" src="" style="width: 100%;height: 500px"></iframe>
    </div>


</body>
</html>